fix: multimedia bottomsheet nav bar color transparency

[criticalAY]

Purpose / Description

It was pointed out by @david-allison when the bottom sheet code was merged as non blocker, hence I am resolving it now, this PR makes the nav bar color transparent.

How Has This Been Tested?

Google emulator API 35:

Learning (optional, can help others)

Resources used: Google M3 docs

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[lukstbit]

LGTM

[david-allison]

Cheers!